Align repo config with global development standards

- Add missing tsconfig strictness flags (noUncheckedIndexedAccess,
  exactOptionalPropertyTypes, noImplicitOverride,
  noPropertyAccessFromIndexSignature) and fix all resulting type errors
- Replace ESLint/Prettier with oxlint 1.48.0 and oxfmt 0.33.0
- Pin all frontend and backend dependencies to exact versions
- Pin GitHub Actions to SHA hashes with persist-credentials: false
- Fix CI Python version mismatch (3.12 -> 3.14) and ruff target-version
- Add vitest 4.0.18 with jsdom environment for frontend testing
- Add ty 0.0.17 for Python type checking (non-blocking in CI)
- Add actionlint and zizmor CI job for workflow linting and security audit
- Add Dependabot config for npm, pip, and github-actions
- Update CLAUDE.md and pre-commit hooks to reflect new tooling
- Ignore Claude Code sandbox artifacts in gitignore

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.beans/nuzlocke-tracker-44ps--replace-eslintprettier-with-oxlintoxfmt.md

@@ -0,0 +1,24 @@
+---
+# nuzlocke-tracker-44ps
+title: Replace ESLint/Prettier with oxlint/oxfmt
+status: completed
+type: task
+priority: normal
+created_at: 2026-02-16T19:13:49Z
+updated_at: 2026-02-16T19:24:15Z
+parent: nuzlocke-tracker-a5es
+---
+
+Global standards require oxlint and oxfmt instead of ESLint and Prettier. This involves:
+
+## Checklist
+- [ ] Install oxlint as devDependency
+- [ ] Configure oxlint with typescript, import, unicorn plugins
+- [ ] Install oxfmt as devDependency (or use oxlint --fix for formatting)
+- [ ] Remove ESLint and all ESLint plugins/configs
+- [ ] Remove Prettier and eslint-config-prettier
+- [ ] Update package.json scripts
+- [ ] Update pre-commit hooks
+- [ ] Update CI workflow
+
+Note: oxfmt may not be stable yet — check current status before proceeding.